SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c398c642f71b2fd8728ac7c34a91786f0573dad319db1b2a1838447f8b71055e' 
  AND token = 'QROcvp6IY0D0hK/WATlwkI0dGRIUoDVw6lrFy1qL+u8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}